Game client will not properly scale up or fullscreen.

So, ever since 6.18, I haven't been able to properly play League. When I boot up a game, it opens in windowed default mode, at the smallest resolution. If I try to fullscreen in the settings, the game tries it, but the window stays. In addition, whenever I try anything other than windowed or borderless, or go to a widescreen resolution, my click space becomes distorted, clicking a sizeable distance from where my cursor is. My health and champion name also appear the the left of my champion model. I'd like to know if this is a known bug, or if this is perhaps a graphics card issue. I have been using this card with league for some time now, so I'd like to think that isn't the issue.